Heavy industrial plants, particularly in the bitumen, heavy oil and petrochemical industries are increasingly being constructed using pre-fabricated modules. A standard module comprises a structural steel frame, and may be 20 feet wide, 80 to 120 feet long, and up to 24 feet high, with weights ranging from 50 to 160 metric tons.
Conventionally, these modules are lifted and installed using cranes and rigging assemblies such as that shown in FIG. 1 (Prior Art). However, as the centre of gravity of the module may not coincide with the physical centre of the module, the rigging must be adjusted so that the module can be lifted with substantially equal tension in the rigging components. The large number of spreader bars, slings and shackles introduce a large number of potential pinch points, each of which carries a potential injury site. The complexity of the rigging causes lengthy delays while adjusting for the module centre of gravity and pick point configurations. The rigging does not provide any stiffness to the module causing significant stresses within the module for unequally loaded modules.
In the conventional rigging assemblies such as shown in FIG. 1 (Prior Art), the slings are provided in the form of flexible cables. When the rigging assembly is not in use, the cables should be detached from the spreader bars and properly stored to prevent their entanglement and for ease of transportation. When the rigging assembly is to be used, however, the cables must be re-attached to the spreader bars. Such operations delay the transportation and use of the rigging assembly.
Therefore, there is a need in the art for a module lift frame which mitigates the difficulties of the prior art.